Research On The Method Of Insertion Loss Compensation Circuit SAW Device

Application of SAW devices have been applied many areas such as mobile communications,broadcasting,television, aerospace, radar and so on,especially the application in the mobile communication equipment, with the rapid development of mobile communication technology, there is an increasing demand for SAW devices.Because of the physical characteristics of the SAW device will generate signal attenuation, which leads to the difficulty of the back-end processing.Commonly compensation circuit often consider only gain promotion, does not take into account input / output circuit matching, resulting in reflection coefficient is too large, serious distortion of phase, even total reflection and no signal output.In this paper, the main content is to find a suitable method to compensate for SAW devices’ insertion loss.Firstly the SAW devices’ input/output impedance are 50Ωand design compensation circuit and simulation; Second non-standard input/output impedance 50Ω SAW devices’ detection, control and compensation of circuit design and simulation, including the capacitive and perceptual distortion detection, control and energy compensation circuit design and simulation.Firstly adopting the grid structure as input matching, this paper introduces the noise cancellation technology coefficient and noise reduction is improved after compensation circuit through ADS2011 software simulation, the simulation results show that the improved compensation circuit can better compensation SAW device insertion loss, good performance and noise and input matching coefficient is low, and the results are compared with the literature of recent years..Then analysis the capacitive mismatch and perceptual mismatch of circuit and simulation. From the simulation results, we can see that the input reflection coefficient and noise figure are not able to satisfy the design requirements. So the impedance of a detection circuitdetects the saw device is a capacitive impedance with inductive impedance, according to the results of the detection circuit of capacitive compensation or is the perceptual compensation, according to the results of circuit simulation, impedance compensation,meet the design requirements of the input reflection coefficient and noise coefficient has great improvement that the compensation method is feasible.